Category: Search Algorithm

Binary search algorithm is better when an array is sorted because it makes comparison between the search key “k” and middle element of the array. Since the array is sorted, the comparison results either in a match between “k” and the middle element of the array or identifying the left half or right half of the array to which the desired element may belong. This process continues on the half in which the desired element may be present in case “k” is not equal to the middle element. In this way, either the element is detected or the final division leads to a half, where the array does not contain the desired element “k”.

This is very efficient method of searching algorithm because the comparison enables one to eliminate half of the elements from further consideration.

Simple way to search for a key value k in an array a is to compare the values of the elements in a with k. The process starts with the first element of the array and k and comparison continues as long as either the comparison does not result in a success or the list of elements in the array are exhausted. This method of searching is known as sequential search or linear search.

The following code example will return the index of the array when a successful search is found for the given key value and when the search is unsuccessful, the function returns -1.